The manufacturing of connected cranks has long inherited conventional appearance designs and craft. With respect to an installation position of a pedal, a position at an end of a crank is flattened, drilled and tapped to manufacture pedal holes having tooth patterns (½*20). As such, when a bicycle is completely assembled and boxed, pedals cannot be directly installed, otherwise the pedals will protrude from two sides of an outer box accommodating the bicycle, hence affecting the boxing process and the overall outer appearance and volume of a carton container. The pedals are then assembled by a client or a specialist after the client purchases the bicycle. Further, a risk of an assembly failure at the client end may be caused due to defective tooth patterns.
Therefore, there is a need for a solution for improving prior art to solve the issues of the prior art.